Coffee machines buying guide

Filter coffee machines come in different cup volumes and are very easy to use. Water simply drips slowly through a basket of ground coffee to infuse in a pot or carafe. There's no need to boil the water first. Filter coffee machines usually have thermos pots and hot plates to keep the coffee warm.

Models have either permanent or paper holders. Permanent filters save you money but they can be messy to clean and can taint. Paper holders are more hygienic and can be simply thrown away after use.

Some filter coffee makers use a 'pod' system. These pods resemble 'tea bags' or foil-encased pods that produce a cup of filter coffee without any mess.

Percolators work the other way around. Ground coffee is put into a holder at the top, water in the bottom. Once boiled, the water is forced up a vertical tube then over and through the filter, with the brewed coffee settling in the bottom of the jug. There's a glass dome at the top so you can see how dark the coffee is becoming. Percolators are ideal for those who want to vary the strength of their filter coffee, though some coffee aficionados consider the coffee not to be as good.

These are steam-driven machines that produce very strong coffee. Espresso coffee is much richer and more concentrated than filter coffee and is the base for a cappuccino or latte. There are two basic types of machines, with pump machines the more expensive.

Pressure machines

Water is boiled in a chamber and this builds pressure and steam. Eventually enough pressure is built up and forces the boiling water through to the coffee. This steam can then be used for frothing. A drawback is that the water used can be too hot to make an authentic espresso. Make sure you check out the bar pressure, as it might not be powerful enough to make
a really good espresso.

Nespresso

This is a 'pod' system that produces espresso coffee. 
The coffee is blended, roasted, ground, and then hermetically sealed in capsules that stay fresh for up to 9 months. They're available by mail order or online. The advantages of this system are that it's an easy way to make coffee, and most major brands of coffee makers have Nespresso systems. There are no messy filter holders to clean, no spillage of coffee granules – and the coffee tastes great! The downside is that you are tied to the supplier's range of coffees, although they usually offer an extensive range.

For the ultimate coffee experience at home, bean-to-cup machines provide you with a sophisticated espresso - and they're also wonderfully easy to use.

Fresh beans are ground and used to make espresso on demand, giving you a truly fresh coffee. Many of these machines are completely automatic: add water to the tank, pour milk into a dedicated container and fill the coffee bean hopper. Then simply press the button for your coffee, and the machine grinds the beans, dispenses your coffee and froths the milk.

Bar pressure

Good bar pressure is essential for making a good 'crema'. It means that the steam meets the coffee granules at the correct speed. Too slow and it could result in a bitter taste. Between 15 – 19 bar is the optimum, though some suppliers claim 9-11 bar is enough if the beans have been ground correctly.

Thermoblock

To achieve an excellent flavour it's important that you don't scald the coffee; rather like a shower, the thermoblock is a type of boiler that heats up the water to the perfect temperature (about 90°C) via a pump. Some models have a thermoblock system for frothing the milk, which needs to be at about 120°C.

Filter holder

This holds the coffee granules and should be kept warm. Basic models have aluminium ones but more expensive models have brass holders that retain the heat for longer.

If you want to imitate the 'baristas' of the Italian coffee bars (experts in the art of making an espresso) it is essential you know how to achieve a perfect 'crema'.

Crema is the pure coffee extract you find on the top of an espresso. Resembling the head you'd find on a glass of stout, it's full of rich aroma and leaves a lingering flavour. A test of a good 'crema' is to put a little sugar on the top. If it takes time to fall to the bottom you've succeeded!

Types of coffee

• Cappuccino: 1/3 espresso, 1/3 hot milk, 1/3 frothy milk
• Latte: with added hot milk. Normally ratio is 1:6 espresso: 
  hot milk.
• Macchiato: espresso with a little touch of milk
• Con Panne: espresso with a dash of cream
• Mocha: hot chocolate with a dash of espresso
• Americano: hot water with a dash of espresso

A good grinder is an important investment. They ensure you have the right size of grain for the coffee you want.

Coffee grinder

Rather like a pestle and mortar these grind beans more evenly. They come in two sorts: wheel or conical burrs. Wheel grinders simply spin very fast and can be a little noisy. The more expensive conical burr grinders spin more slowly, tend to clog less and are also quieter.

Buying coffee

Little and often is the rule of thumb. Coffee loses its freshness very quickly.

Storing coffee

It's recommended you store your coffee beans or grounds in a glass, airtight container, away from bright sunlight, as it can reduce freshness. For consumption within one week, room temperature is fine. For two weeks to a month, keep your coffee in the fridge. This prevents the chemical reactions that produce stale beans and lifeless coffee.